car is a STOCk 1988 gxl. i have searched on this problem, but couldn’t find any solutions, in most cases the car had been modified.

ive been trying to pass smog, with no avail.

the car has a misfire at idle, also if i hold the rpm anywhere from 1k to 2k there is more misfires.

any help is appreciated.

thanks

 

links is broke. and the video it's supposed to link to has no image either...

 

For some reason I think that's normal? It doesn't look THAT bad... and i've seen worse

 

I'll bet that your Plug wires are Mixed up..the TRAILING WIRES are reversed...change your plugs too,and see if that helps.

 

give it a tune up. new plugs, wires, and maybe a new o2 sensor.

 

replaced: plugs and O2 sensor.
im waiting for my new ngk spark plug wires to show up.

if i do somehow have the wires wrong, let me clarify.

the coil in the left front fender well area is for the bottom two spark plugs correct?
what else could cause a misfire?

 

ok maybe, but this is most likely why the car wont pass smog.
my Hydrocarbon levels are way to high, and that is mainly caused by unburnt fuel, thus a misfire.

 

it should say T1 T2 L1 L2 in the coils somewhere

 

if it says l1 and l2 then yes. those goe to the bottom of the housings.

 

Sounds more like a spark-related misfire than fuel mixture. I'd change the plugs and make sure there aren't any plug wires touching each other or anything metal, especially no plug wires cable-tied together. A popular mistake. Run the engine at idle on a dark night and look for arcing anywhere along the plug wires/ coil towers/ plugs. Blip the throttle a few times, arcing can occur under load, especially on a cold engine when spark demand is greatest.

Also, is your hot idle always at 1750 rpm? do a propane check for vacuum leaks.

 

High hydrocarbons can be the result of overadvanced spark timing, ignition-related misfires, too rich fuel mixtures, and, believe it or not, too lean fuel mixtures. Lots of people don't get that last one though. I can explain it, but perhaps tomorrow. I'm off to bed.

 

Checked the wires, they are correctly installed. They have a plastic shield on them, but they are next to each other.
When my new ones arrive I will make sure to keep them apart.

["Also, is your hot idle always at 1750 rpm? Do a propane check for vacuum leaks."
No I had the idle set that way so I could walk around. I used some pliers kinda, basically if someone had their foot on the pedal. ]


I checked for fuel mixture by doing the propane trick, hooking it directly in line with a vac line, and the idle went up slightly with very little propane, any more and it started to bog, and from what I gather that’s about right.

Also shot some around any vac lines and it had no effect, so I don’t believe I have any vac leaks. I have changed as much vac line as I can with out damaging anymore fragile plastic.

I changed plugs two days ago. Question though, what plug is hotter the 9's or 7’s?
And 7’s on leading and 9’s on trailing, yes?

 

This might qualify as a retarded question at this point, but do you have your catalytics intact? If not, try replacing them.


Seriously- old car=old catalytics=poor filtration from catalytics, even if no one has messed with them.

 

i have other threads up that are related more towards the emissions filing part

link: https://www.rx7club.com/showthread.p...51#post7085951

but because there is a video on this one im getting much more attention, hehe

 

If more people used videos in their posts, we would be able to help them so much easier.

Oh and rotorpower27, that is an awesome animated sig pic!

 

yeah 7's leading and your 9's trailing on the plugs

 

, here is another symptom my car has.

If I hold the idle anywhere from 1k to 1.5k rpm the rpm begins to bounce up and down.
what would cause this, and could it be related?

 

My car has that same problem. If I use very light throttle anywhere from 1500 - 2000 rpm the car revs up and returns to 1000. It makes for going into reverse slowly very awkward. Check all the basic stuff, TPS, BAC, O2, yadda yadda whatever. Let me know what you find out! :p

 

Hey! Your exhaust sounds exactly like mine... and I bet you paid a lot more for it too :-P. It's normal for higher mileage rotaries to do that, like mine. And in the second video- your tps (throttle position sensor) is probably badly mis-adjusted and/or it's shot and is leaking. Try replacing it with another one known to be good and it should go away. I've been through 2 tps's that had the 1500 rpm loop.

 

I never knew TPS could leak...what exactly are they filled with??

 

TPS can't leak. Impossible when there is nothing to leak out.

Sounds normal to me. If you didn't pass smog, check your emmisions equipment. Look in the FSM. I have noticed that the ACV check valve gets clogged up with carbon and gunk and either needs to be cleaned or replaced for it to function correctly.

Your bouncing idle is your TPS. Sounds to me like its not incorrectly adjusted or has a dead spot.
Check your TPS
http://howto.globalvicinity.com/gv_w...i=58&co=1&vi=1

 

i have pulled the tps off the car and have checked the entire sweep of its motion, it was fine.

as for the ACV, this part is connected to the driver side of the intake manifold correct?

 

Did you check the adjustment though? While the TPS is on the TB, check to make sure its .95K - 1K ohm.

 

Throttle Position Sensors do not leak. It is only a drum sensor...

 

I had a pulsing idle from 1k - 1.5k rpm, then I adjusted the TPS, and BAM, almost perfect idle. just be sure to warm up the car before you adjust it!